Hand hygiene has risen in importance in recent years in response to the increased incidence of infection in hospitals by such resistant organisms as MRSA, and in recognition of publicized incidents of infection in closed communities such as cruise liners. In hospitals a common route of transmission of such organisms is via the hands of health care workers. The World Health Organisation (WHO) has produced guidelines on hand hygiene: “WHO Guidelines on Hand Hygiene in Healthcare” Advanced Draft 2007 (referred to herein as WHO Guidelines). According to the WHO Guidelines, human skin is populated by two broad categories of microorganisms, namely resident and transient. Resident organisms reside under the superficial cells of the stratum corneum, and also on the surface of the skin. Staphylococcus epidermis is the dominant species. In general resident organisms are less likely to be associated with infections but may cause infections in sterile body cavities, in the eyes or on non-intact skin. Transient organisms which colonise the superficial layers of skin are the organisms most frequently associated with health care associated infections, and common transient microorganisms are for example S. aureus, other Staphylococci, Clostridium difficile, E. coli and various viruses such as rotavirus, influenza viruses and rhinovirus.
As a response to transmission and cross-contamination of microorganisms by persons with infected hands such as hospital care workers, efficient washing of local inanimate surfaces such as furniture and workers' hands using a sanitising formulation is the most common proposed solution. Such sanitizing formulations are generally in the form of mobile liquids or gels which can be conveniently applied to such surfaces, suitable viscosities for such formulations being well known in the field. Numerous sanitising formulations are known for example as disclosed in WO-A-2004/101724, WO-A-2004/101725 and WO-A-2005/110357 being typical examples. Some known sanitizing formulations are based on combinations of surfactants, such as sodium lauryl sulphate, and certain acidic polymers such as so called Carbopol. Such formulations are for example disclosed in WO-A-1999/24012, GB-A-2 393 908, EP-A-1 090 631 and WO-A-2005/04663.
The WHO Guidelines also list numerous substances which have been used for hand sanitising in an attempt to decontaminate skin from harmful organisms, including soaps, alcohols, chlorhexidine, chloroxylenol, hexachlorophene, iodine, iodophors, quaternary ammonium compounds, triclosan, hypochlorites etc. Some of these substances are associated with hazards, for example alcohols are inflammable and iodine and other halogens can be corrosive or release for example free chlorine gas.
It is known for example from applicant's co-pending PCT/EP2007/057298, WO-A-03/039713 and U.S. Pat. No. 7,029,516 that certain acidic polymers have virus deactivating activity and can be deposited onto fibrous substrates for us as air filter systems. It has unexpectedly been discovered that by formulating acidic polymers in specific novel ways sanitising formulations having both anti-viral and anti-bacterial activity may be provided. It is an object of the invention to exploit this discovery in the provision of improved sanitising formulations, for example having improved efficacy, or efficacy against a wider range of microorganisms, or avoiding the disadvantages associated with known sanitising formulations.